Clock



FIG. 1 is a front elevational view of a clock showing my new design;

FIG. 2 is a front elevation thereof with digital display.

FIG. 3 is a rear elevational view thereof.

FIG. 4 is a top plan view.

FIG. 5 is a left side elevational view thereof, the right side being substantially a mirror image.

FIG. 6 is a bottom plan view.

The broken line showing of an hour and minute hand is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a clock, substantially as shown and described. 